Applications:

HPLC Separation of Mixture of Paraquat and Diquat

Paraquat and diquat are two of most widely used herbicides in the world. Both compounds are toxic for humans and animals. Presence of paraquat and diquat in water is regulated by EPA. Paraquat and diquat have two quaternary amines, making them very polar molecules. Paraquat and diquat also have similar formula. Due to low hydrophobicity and highly basic properties, they show limited retention on reversed-phase columns and produce very poor peak shape due to the residual silanol interactions. Primesep AB and Obelisc R column retain and separate these two compounds with perfect peak shape.

HPLC Separation Paraquat and Diquat on Obelisc R

Paraquat and diquat are two of most widely used herbicides in the world. Both compounds are toxic for humans and animals. Presence of paraquat and diquat in water is regulated by EPA. Paraquat and diquat have two quaternary amines, making them very polar molecules. Paraquat and diquat also have similar formula. Due to low hydrophobicity and highly basic properties, they show limited retention on reversed-phase columns and produce very poor peak shape due to the residual silanol interactions. Primesep AB and Obelisc R column retain and separate these two compounds with perfect peak shape. Method can be used for analysis of paraquat and diquat in soil, ground and drinking water, and other samples. Method allows to separate both compounds in one run without ion-pairing reagent.

Separation of Paraquat, Diguat, and Glyphosate on Obelisc R Column

Paraquat, diquat and glyphosate are three of most widely used herbicides in the world. Paraquat and diquat are very polar and very basic quaternary amines. Glyphosate is an aminophosphonic analog of glycine. It is very polar and acidic at most of the pH of the mobile phase. Since glyphosate and the quats have opposite charges no ion-pairing method can be developed for the mixture of basic and acidic herbicides. All three herbicides were separated on the Obelisc R tri-modal column. Paraquat and diquat are retained by a cation-exchange mechanism, and glyphosate is retained by weak reversed-phase and strong anion-exchange mechanisms. This method can be used for analysis of common herbicides in fruits, vegetables, ground water, drinking water and other matrices. Method is LC/MS compatible and can be used to determine trace levels of herbicides.

Description

Paraquat Diquat Separation in Non-aqueous Mobile Phase

Paraquat, diquat and glyphosate were separated on reversed-phase tri-modal cation- and anion-exchange column (Obelisc R) and on HILIC/ion-exchange columns (Obelisc N). Method explores unique properties of mixed-mode stationary phase which retains and separates cations like paraquat and diquat and anions/zwitter-ions like glyphosate in one run. Since columns are compatible with 100% organic and 100% water, a wide range of gradients can be used for analysis as well as isocratic conditions where it is desired. Method can be used for quantitation of these compounds in various matrices (soil, ground water, crops, food, etc.)

Description

Separation of Herbicides Paraquat, Diquat and Glyphosate in One Run with LC/MS Compatible Conditions

There is a need to separate different herbicides and pesticides in one run with LC/MS compatible conditions. Paraquat, diquat and glyphosate were separated on reversed-phase tri-modal cation- and anion-exchange column (Obelisc R) and on HILIC/ion-exchange columns (Obelisc N). Method explores unique properties of mixed-mode stationary phase which retains and separates cations like paraquat and diquat and anions/zwitter-ions like glyphosate in one run. Since columns are compatible with 100% organic and 100% water, a wide range of gradients can be used for analysis as well as isocratic conditions where it is desired. Method can be used for quantitation of these compounds in various matrices (soil, ground water, crops, food, etc.)